From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 24 Mar 2003 14:43:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 24 Mar 2003 14:43:19 -0500 Received: from mail3.efi.com ([192.68.228.90]:10771 "HELO fcexgw03.efi.internal") by vger.kernel.org with SMTP id ; Mon, 24 Mar 2003 14:43:17 -0500 Message-ID: <3E7F61D6.D1017E70@efi.com> Date: Mon, 24 Mar 2003 11:51:50 -0800 From: Kallol Biswas X-Mailer: Mozilla 4.76 [en] (X11; U; Linux 2.4.2-2 i686) X-Accept-Language: en MIME-Version: 1.0 To: Linux Kernel Mailing List Subject: usb printer driver and zero length transfer Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, I am new to USB world and looking for clarification on usb printer's behavior when transferring data with size multiple of wMaxPacketSize. I have been running redhat 7.1 (linux kernel 2.4.2-2) on x86 PC with a USB 1.1 controller. There is a target mode printer driver running on the other side. On the host the device file is /dev/usb/lp0. If a data packet of 64 bytes is sent with "cat data8 > /dev/usb/lp0" , the size of data8 is 64, a zero length packet at the end of the transfer is not sent. Is this a correct behavior? How do we force the printer driver send a zero length packet at the end of a transfer if the packet size is a multiple of wMAxPacketSize? Kallol